Platelet concentration syringe kit

ABSTRACT

A single-use system for separating blood and producing platelet concentrates includes an elongated container for receiving blood from a patient. The container has a movable plunger mounted within the blood container for expressing blood fractions separated during centrifugation of the container through a first port mounted at one end of said container, a second port mounted on the plunger, and a third port mounted on a plunger rod attached to the plunger.

FIELD OF THE INVENTION

[0001] This invention relates to processing whole blood into fractionsand, more particularly, to improvements in blood processing systems forseparating platelet-rich plasma from autologous blood.

BACKGROUND OF THE INVENTION

[0002] The science and effectiveness of using platelet-rich plasmaderived from the patient's own blood in surgery are documented inmedical, trade, and science journals. A known method for the preparationof platelets from whole blood is described in the American Associationof Blood Bank's Technical Manual, 12 th Edition, 1996, at pages 700-701,Method 9.11. A system employing this method collects the patient's wholeblood into a collection unit with two integrally attached transfercontainers. The blood is collected into the collecting container, theother two transfer containers are collapsed, and the two transfercontainers with the collecting container are subjected to a “soft spin”in a centrifuge, which brings the plasma to the top of the collectingunit, leaving red cells at the bottom. In the next step, the collectingcontainer containing the blood fractions are squeezed in a plasmaextractor to force the platelet-rich plasma into one of the transfercontainers through a connecting tube. A fraction comprising red cellsremains behind in the collecting container, which is then removed. Next,the two transfer containers, the first being empty and the secondcontaining the plasma, are subjected to a “heavy spin” in a centrifugeto concentrate platelets at the “bottom” of the second transfercontainer, leaving a platelet-poor fraction of the plasma (PPP) abovethe platelet concentrate (PC) in the second transfer container. Thefollowing step squeezes the second transfer container to express the PPPinto the first transfer container. The platelet concentrate (PC) is thenresuspended and collected for use. This system uses a process requiringsix separate steps, including two centrifugal steps and two separationsteps. The terms “light spin” and “heavy spin” are defined in Table10.5-1 at page 716 of the AABB Technical Manual.

[0003] An alternative method of separating blood fractions is discussedin U.S. Pat. No. 5,102,407 and referred to as the “Amsterdam” method.Instead of two spins, soft then hard, as discussed above, a single hardspin is used in which three fractions are separated, that is, arelatively platelet-free plasma, red blood cells, and an intermediate“buffy coat” layer which contains platelets and leukocytes.

[0004] The usual procedures often employ pliable plastic bags which makeit difficult to separate the blood fractions accurately. Consequently,improvements have been needed. The present invention is embodied in anew blood separation kit which provides a more convenient and efficientmeans for separating a patient's blood and in particular for recoveringplatelets.

SUMMARY OF THE INVENTION

[0005] The invention provides a single use system for separating bloodand preferably for producing platelet concentrates (PC). In oneembodiment, the system is in the form of a syringe kit includingdisposable components supplied in sterile disposable packaging, andhaving all of the components required to draw blood from the patient,prevent blood coagulation, separate the sample into fractions includingplatelet concentrate, and deliver the platelet concentrate to a surgicalsite. More precise separation of the separated blood fractions ispossible, compared to the results achieved with pliable plastic bags.Such a system will be useful to medical and dental practitioners.

[0006] The invention may be generally described as including anelongated container, preferably cylindrical, which is adapted to beplaced in a centrifuge for separating the fractions of blood introducedinto the container. The container is equipped with a first port throughwhich the blood fractions can be expelled by a plunger movably fittedwithin the container. The first port is located at a first end of thecontainer and a second port is located on the movable plunger. Bothports are normally closed and they are opened from outside the containeras required for removal of blood fractions. The plunger is equipped witha detachable hollow plunger rod adapted to open the second port when theplunger rod is attached to the plunger. A third port is mounted at theend of the plunger rod, the third port also is normally closed unlessopened from outside the plunger rod.

[0007] In one embodiment of the invention, the container is in the formof a syringe barrel fitted with a moveable plunger. The syringe barrelis charged with a patient's blood and all of the centrifugal andseparation steps are performed while the blood is in that container. Thesyringe barrel is adapted for use in a centrifuge, and has valves fittedat one end and within the plunger, making it possible to collect blood,centrifuge the blood in the syringe barrel, expel red blood cells afterthe first or soft spin, centrifuge the remaining platelet-rich plasmaand expel platelet-poor plasma after the second or hard spin. Theplatelet concentrate remains in the syringe barrel, where it can beresuspended in a medium or media that can be introduced into thecontainer through one of the valves.

[0008] In another embodiment, the container of the invention is given a“hard” spin, omitting the “soft” spin. Three fractions are formed, thefirst fraction, the red blood cells, is expelled through the first port,then the second fraction, platelet-poor plasma, is expelled through thesecond and third ports, leaving the third layer, consisting of plateletsand plasma, for further processing.

[0009] The separation of blood fractions may be carried out manuallyafter centrifuging the whole blood in the container. Alternatively, theseparation of blood fractions could be carried out automatically incentrifuge equipment having facilities for opening the ports after ithas been determined that the desired separation has been made.

[0010] Associated with the container preferably will be a needleassembly for drawing a patient's blood and which is adapted to transferthe blood into the syringe container directly or into a separatecontainer for subsequent transfer into the syringe container. One ormore waste bags adapted to receive platelet-poor plasma and red bloodcells from the syringe cylinder after the soft and hard spins may bepart of the syringe kit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is an isometric view of a elongated syringe container andassociated components.

[0012]FIG. 2 is a longitudinal section through FIG. 1.

[0013]FIG. 3 shows a blood-collector needle.

[0014]FIG. 4 shows a waste bag.

[0015]FIGS. 5a through 5 e show use of the syringe embodiment to prepareplatelet concentrate.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0016] The figures illustrate a syringe embodiment of the inventionadapted for manual handling in separation of blood fractions. Blooddrawn from a patient is introduced into a syringe, the syringe is placedin a centrifuge and spun at the appropriate speed for a suitable periodof time to cause the blood to be separated into at least two fractions.Alternatively, the separation may be automated and the blood fractionsseparated without manual handling of the syringe container.

[0017]FIG. 1 shows an elongated container 10, bearing graduated marks 12to indicate the volume of its contents (not shown). The container has afirst port, shown in the drawing as including a spring-loaded ball seatvalve 14, at a first end 16 and a radially-extending flange 18 at itsother end. A plunger 20 fits slidably within the container and preventsblood from passing between the wall of the container and the plunger.The plunger has a through passage 22 fitted as a second port, also shownas a spring-loaded ball seat valve 24 (FIG. 2). The valve 24 could beomitted if desired, in which case, it would be necessary to temporarilyseal the opening while the container is being centrifuged to separatethe blood fractions. A tubular plunger rod 26 is adapted at one end 28to engage the spring-loaded ball seat valve 24. The plunger rod hasanother spring-loaded ball seat valve 30 at its other end remote fromthe plunger. The valves 14, 24 and 30 may have a “Luer” fitting, whichhas a coupling 15, 25 and 31, respectively, for removably connecting toanother article (for example, a hose). This type of valve is normallyclosed when nothing is connected to its coupling, and the valve can beopened when the protruding feature of a mating connector forces the ballaway from the valve seat. It should be understood that the valves neednot be the spring-loaded ball seat valves shown in the drawings, but maybe other types capable of preventing the escape of the blood componentsand of being opened when needed, for example a valve in which a siliconeplunger seals against a conical valve seat, the compression of whichcloses the valve until activated. More broadly, the ports may includeother means for blocking flow of the blood components rather than thevalves in the figures.

[0018] The container 10 and associated parts of the kit, particularlythe plunger 20 and plunger rod 26, differ from conventional pliableplastic bags in being made of relatively stiff materials, for examplepolycarbonate, polypropylene, ABS or equivalents. It is an advantage ofthe present invention that, since the container walls are relativelyrigid, the problems associated with separating blood fractions in apliable bag are avoided. Moving the plunger within the container createsminimal disturbance of the separated blood layers, thereby enabling amore precise separation to be made.

[0019]FIG. 3 shows a needle 32 for taking blood from a patient connectedto one end of a tube 34 which has at its other end a fitting 36 that isadapted to connect to any of the couplings 15, 25 or 31. Thus, blood maybe introduced directly into container 10 through valve 14 oralternatively, blood may be directed to a separate bag for subsequenttransfer into the container for separation.

[0020]FIG. 4 shows a waste bag 40, typically but not necessarily apliable plastic bag, connected to one end of a tube 42 which has at itsother end a fitting 44 that is adapted to connect to any of thecouplings 15, 25 or 31, thereby opening the associated valve. The tube42 is fitted with a tubing clamp 46. The container 10 and associatedparts shown in FIGS. 1-4, inclusive, comprise the syringe kit of thisembodiment of the invention. The container 10, shorn of associated parts(plunger rod 26, needle 32 and tube 34, and waste bag 40 and tube 42)may be adapted for fitting in a centrifuge bucket (not shown) and usedto separate blood into its fractions and to prepare plateletconcentrate, as is described with reference to FIGS. 5a-5 e, inclusive.

[0021] In FIG. 5a, the plunger 20 is at the top of the container 10,near the flange 18, the needle 32 is connected to check valve 14, whichis held open, the waste bag 40 is connected to the plunger check valve24 holding that valve open, and the clamp 46 is open. The container maybe empty or it may contain a small amount of a blood anti-coagulant.When the needle 32 draws blood from a patient, the blood flows into thecontainer under pressure from the patient, displacing air from thecontainer 10, which air is received in the waste bag 40. When thecontainer 10 is charged with blood, the waste bag 40 and needle 32 aredecoupled from the valves 14 and 24, which are closed by the associatedsprings. Alternatively, the waste bag 40 is not used and instead, theplunger 20 may be used to extract blood directly from the patient in amanner similar to a conventional syringe. The container is subjected toa light spin in a centrifuge (not shown). As is shown in FIG. 5b, thisstep separates red blood cells (pRBC) from platelet-rich plasma (PRP).In the next step, shown in FIG. 5c, the waste bag is connected to valve14, and the plunger rod 26 is connected to the plunger via the valve 24.The valves 14 and 24 and the waste bag clamp 46 are all open, but thevalve 30 at the free end of the plunger rod is closed. The plunger rod26 is used to push the plunger into the container, expelling the redblood cells into the waste bag 40. The container now contains primarilyplatelet-rich plasma. The clamp 46 is closed, and the plunger rod andthe waste bag 40 are decoupled from the container, thus closing valves14 and 24.

[0022] The container 10, shorn of the bag and plunger rod, as shown inFIG. 5d, is next subjected to a hard spin, which concentrates plateletsat the bottom end 16 of the container 10, leaving platelet-poor plasma(PPP) above the platelet concentrate. The final step in the process,that of removing the platelet-poor plasma from the container, isillustrated in FIG. 5e. The plunger rod 26 is again attached to theplunger 20, and the waste bag 40 is coupled to the free end of theplunger rod through the valve 30. The valves 24 and 30 and the clamp 46are all open, and the valve 14 is closed. The plunger is driven towardthe lower end 16 of the container, and the platelet-poor plasma isforced through the passageway in plunger rod 26 and the tube 44 into thewaste bag. The clamp 46 is then closed, and the waste bag 40 and, ifdesired, the plunger rod 26 may be removed from the container. With thewaste bag removed, the plunger rod valve 30 will close, so failure toremove the plunger rod will not affect the contents of the container.The container 10 is now left with the platelet concentrate in it.

[0023] The above description covers a simple manual operation in whichthe syringe kit is used in a particular manner to separate blood intothree fractions by successive soft and hard spins. It is also feasibleto use only one “hard” spin to separate the blood in a single step intothree fractions (i.e., red blood cells, plasma and an intermediate layercontaining platelets). The three fractions can be separated by expellingboth the plasma and red blood cells separately or simultaneously,leaving the intermediate layer for further processing. Alternatively,such manual operations can be automated.

[0024] It should be understood that the syringe kit described above is apreferred embodiment, but that modifications may be made withoutdeparting from the scope of the invention as defined by the followingclaims.

1. A blood separation kit comprising: (a) an elongated hollow containerhaving a first end and a second end and comprising a first port mountedat said first end for admitting liquid to or expelling liquid from saidcontainer, said port being closed unless opened by a fitting attached tosaid port; (b) a plunger movably disposed within and engaging the wallsof said container of (a), said plunger comprising (1) a passagewaythrough said plunger communicating with the interior of said containerof (a), and (2) a second port for expelling liquid mounted within saidpassageway of (b)(1), said port being closed unless opened by a fittingattached to said port; and (c) a plunger rod having a passageway thereinand adapted to engage said plunger of (b), said plunger rod comprising(1) means for engaging said plunger to provide communication with theinside of the container of (a) via the passageway in the plunger of (b)to the passageway in said plunger rod, (2) a third port for expellingliquid mounted at the end of said plunger rod opposite said means forengaging said plunger, said third port being closed unless opened by afitting attached to said third port.
 2. A blood separation kit of claim1, further comprising: (d) a needle set comprising: (1) a hollow needlefor taking a sample of a patient's blood; (2) a hollow tube attached toand communicating with said needle for transferring said patient's bloodto the container of (a); and (3) a fitting adapted to engage the firstport of (a) and to open said first port.
 3. A blood separation kit ofclaim 1, further comprising: (e) a waste bag having a hollow tubeconnected to and communicating with the interior of said bag forreceiving separated blood fractions; (f) a fitting adapted to engage thefirst and third ports (a) and (c)(2) respectively and to open said firstand third ports; and (g) a clamp mounted on the tube of (e) for openingand closing the hollow tube of (e).
 4. A method of collecting andseparating a patient's blood and recovering a platelet-rich concentratecomprising: (a) collecting the patient's blood using a needle setcomprising a hollow needle having attached tubing and a fitting adaptedto engage a first port in an elongated container fitted with a movableplunger having a second port therein; (b) transferring said bloodthrough said first port into said elongated container; (c) centrifugingsaid blood in said container and separating said blood intoplatelet-rich plasma and red blood cells; (d) displacing the red bloodcells separated in (c) from said container by moving said plungertowards said first port and expelling said red blood cells into a wastebag through tubing attached to said first port; (e) removing said wastebag of (d) centrifuging said platelet-rich plasma remaining in saidcontainer and separating a platelet-rich concentrate from aplatelet-poor plasma; (f) attaching a hollow plunger rod having a thirdport therein to said plunger and displacing the platelet-poor plasmaseparated in (e) from said container by moving said plunger towards saidfirst port and expelling said platelet-poor plasma through said secondport of said plunger and said third port of said plunger rod into awaste bag attached to the plunger rod; and (g) recovering theplatelet-rich concentrate separated in (e) and remaining in saidcontainer.
 5. A method of collecting and separating a patient's bloodand recovering a platelet-rich concentrate comprising: (a) collectingthe patient's blood using a needle set comprising a hollow needle havingattached tubing and a fitting adapted to engage a first port in anelongated container fitted with a movable plunger having a second porttherein; (b) transferring said blood through said first port into saidelongated container; (c) centrifuging said blood in said container andseparating said blood into platelet-poor plasma, red blood cells, andplatelet-rich concentrate; (d) displacing the red blood cells separatedin (c) from said container by moving said plunger towards said firstport and expelling said red blood cells into a waste bag through tubingattached to said first port; (e) removing said waste bag of (d) andattaching a hollow plunger rod having a third port therein to saidplunger and displacing the platelet-poor plasma separated in (c) fromsaid container by moving said plunger toward said first port andexpelling said platelet-poor plasma through said second port of saidplunger and said third port of said plunger rod into a waste bagattached to the plunger rod; and (f) recovering the platelet-richconcentrate separated in (c) and remaining in said container.
 6. A bloodseparation kit of claim 1, wherein said first, second, and third portscomprise valves positioned to to prevent expelling blood fractionsduring centrifugation of blood in said container.
 7. A blood separationkit of claim 1, wherein said ports comprise Luer fittings.